Electrothermal protector.



- P. B,t 000K.

ELEGTROTHERMAL Plwflcilfo.v

APPLIOTION FILED MAY 23,. 1967.

PATBNTED JUNE .23, w08.

` Beit known that l, FRANK UNITED er'.irEs

rfiiiixi; B. cooit, or

PATENT OFFICE.

unicaen, ILLINOIS.

ELECTROTHERMAL PROTECTO.

Nasen/ies.

Specification of Letters Patent.. Patented Jnne'23, 1908.

Appiicaaon fried May 23, i907. semi No. 375,282,

T mail iciom it may' con-cern.'

B.Cooit,a citizen oi thetinited States of Americaresiding 'at Chicago. in the cduntv otCook. and State of'lllinois, have invented a new and useful Electrotherinal Protector, oi' which the following is a specification, reference being had to the accompanying drawings, illustrating Stlllle.

` Mvinvention relates to protectors and protective apparatus for protecting electrical circuits and apparatusgi'roin abnormal 'currents and potentials of electricit v.

The principal objects ofinv invention 'are I' to provide .asiinplifiedand compact Vprotector of the character speciiiedg' to Iprovide impro-ved means for grounding the ine circuit upon the operation of the protector; to

irovide improved means for 4mounting the lightning arrester oi the protector in place; to provide i'nipitn'ednieans for operating the thermal protector of the apparatus upon cX- cessive heating; to' provide improved means whereby the thermal protector majbe rea dil v reset after operation for anotlleifoperation; Y and 4to Vprovide improved means y for closingan alarm circuit when the thermal protector operates..

Other obfects will belapparent from the followingl specification.

. B v reference tothe accompanying drawings illustrating the preferred iorm oi in v insprings 50 ven'tion, Figure 1 a plan-view oi a pair of duplicate sets of the protective apparatus mounted upon opposite sides of a ground plate; Fig. 2 is a iront edge elevation of F ig.

1, showing a series' of lightning arresters laced against the ground plate; lFig. 3 is a oiigitudinal crosssect1on of the thermal protector and lightning arrester shown in Figs.

1 and 2, with portions shown in elevation;

ground plate.

being arranged on the opposite side' of the bushing 10 is placed lietween springs 1 and 2 so that spring 2 ina v have a slighttension toward springl and at `thi` sainer time normali)v remain out ot con tact with spring 1 as shown on'tlie left of Fig. 1. It is'desirahle to have this-tension in spring 2 so that in assembling it is not re.-

quired to accurately adjust spring 2 to noi'- inallv keep it` out of Contact with'springs 1 and Bas shown on the-left of Fig. 1.

The thermal protector comprises 4ani-iiclosing shell 11 containing a resistance element 12, a contactplatc 13and a terminal 1.1, the parts 12, 13 and 1-1 being suitably *insulated from the casing 1 1 and the resistanCe'elenient 12 making contact' with end 15 vof the casing. This construction 'is shown,

described and claimed in my ct'ipendingap;

plication for Letters Patent on E cctro-Thermal Protector7 Serial Xo. 316,153, 'filed- Mav 10,1906. The-tcrniinallli's provided with a head 1.6 against whi'clispring 3 presses as shown iii Fig. 1, to provide an operable. contact for testing purposes. is'provided with a pin lextending from the end 1 5t hereof, which pin extends through The casing 11 a hollow neck portion 18 cxtendingvfrom the-f end' of a metallic cup-shaped'portion 19 I I i which incloses the said shell 11 and which is cemented to.v the portionll at 20 by 'a suitable heatsusceptihle cement, preferably a metallic solder. The n eck portion 18 guides `thepin 17and is provided with an annular flange 21 thereon wliichbears against the outer 4carbon block 22 .of the ligl'itning ar-V rester so as lto malte good electrical connecf- `tion therewith and hold the carbons-2-2and 23 and tlieydielectrief24 thereof in place against the ground plate 1, the lattcir electrieall)- engaging the carbon' 23. 4The carbon 22 is provided Vwith a cei'itral hole therein in'which't-he iieclt.}')oition 1S extends, prefer' ably assliown in 3,1so that the pin 17 may freely move through the neck portion 18 wit/hout engaging tliecarbon 22 and being hindered thereby. Line. spr-ing 1 ,enga'ges the -neclt p-ortion'18 in the 'annular recess 25, the spring -1 having ajslot 26 for receiving the neck portion anda split27- extending therefrom to cause the portions' along the slot 26 to firmly grip the neck portion. The carbon 23"flien inserted into the'apparatus rests in a cut-out portion in tlie end of insu- .lating stripZS, which keeps, the-.carbon 23 in alinement, the-latterbeing rovided with ay large hole 31 therein throng 1 which the pinl 17 extendsv andwhich prevents the pin 17 mal protector operates.

It willbe seen from Fig-2 that the carbon blocks 23 23 in a series or li htning arrestersmounted along Athe groun plate 4, fit in' close to each other s'o as to help keep them in alinement.' The line carbons 22 22 are somewhat smaller than the Icarbons 23 v23, to rovide clearance between them as shown m ig. 2. i

Theo eration of the ap aratus is as follows: en an v4abnormal y large current traverses the heat-producing element, or resistance element, 12 of a'thermal protector, such current' generallyA coming ron'ra line spring 1 and assing through' the thermal protector'l to` the switchboard spring 3, thc resistance element v12 produces heat, which heat, when sidiicient, softens the heat-susceptible material, 20 y'which then allows the casing 11 to move Within the. cup 19. Now the switchboard spring 3 bearin against the head 16. pushes the thermal e ement as a Whole farther into the cup 19 until the end of pin 17 engages the ground plate' and thereby grounds the line spring 1 which switches. the objectionable 'current oil?v to groundthrough the pin 17 and the ground plate 4, thereby diverting the .said objectionable current from the thermal protector and from the circuitand apparatus connected with 'spring 3. The operation of spring 3 also causes same to engage contact 30 Aand 'operate spring 2 until contact 29 thereof engages spring 1, thus closing a suitable alarm circuit between springs 1 and 2 togivea si nal in the usual manner to indicate that t e'apparatus. has operated, and also preferably grounding the switchboard spring 3. .Spring 2 is preferably thin and .is preferably cut away at'32 so that after con.- tact 29 engages spring 1', the portion 30 may be still farther depressed by spring 3,unti1' the pin 17 iirmly engages the ground plate 4. When it is desired to reset the thermal protector for another operation,- the same may be heated in any suitable manner, either mechanically or with an electriccurrent, and the parts iroperly restored to the position shown 4in ig. 3, the heat-susceptible material 20 being then allowed to cool and therebycement the portions 11 and 19 together as originally..4v

Electricity of high potential coming to the protector over line spring 1, when the thermal protector is set passes through the carbon,j22,zthe dielectric 24 and the carbon 23 to ground through the ground plate in the f desired, the alarm springs 2 2 may be done away with entirely, where same are not required, Without 1n any manner affecting the remainder of the protective apparatus or the operation and functions thereof.

I do not wish to limit this invention to the particular details of construction as herein shown, either in the apparatus asa whole or 1n anyof the arts thereof, as many modifications may e Inadein samewithout 'depqarting from the sco e of the invention.

either do I Wish to hmit this invention to any particular cementing material in the thermal protectors, no r to,V the particular switchin of the line circuits as herein shown. What claim as my invention and desire to secure by Letters Patent is:

1. In apparatus of the character described,

a ground plate, s ring members mounted uponthe ground p ate near one edge thereof and suitably insulated from each other, a lightning arrester comprising a pair of electrodes held against the other edge of the ground late by one of the said springs, a thermal y-oper'able device held in close proximity to the lightning arrester b v the said'springs, and an operable member extending through the electrodes of the lightning arrester to engage the ground plate when the thermally-operable device is operated, whereby one of the said spring membersI is grounded.'

2.A In apparatus o'' the character described, a ground plate, a lightning arrester comprising two carbon disks one of which. is held able device held in close proximity to the ,lightning arrester,` means for operating the thermally-operable device upon excessive' heating, and a pin project-ing from the said thermally-oporable device through the electrodes of the lightning arrester to' engage the ground plate when the thermally-operable device is operated, for purposes substantially as described.

3. In apparatus of the character described comprising a ground plate and spring members mounted thereon, a lightning'arrester inserted into the apparatus near oneedge of the ground plate and vengaging'the latter, a strip of insulation `lying along the ground plate to limit the insertion of the lightning arrester, and a thermally-operable device carried by the said spring members and hav- `ng a pin extending into the lightning arrester, the .said pin being operated by one of the spring members to contact the ground plate upon abnormal current conditions in .the thermally-operable device, whereby one .of the said spring members is grounded.

4. In apparatus of the character described, a ground plate, a pair ofspring members mount ed thereon and suitably insulated from each other, a thermally-operable:device car-` ried b vthe said pair of springlmembers and having a contact member adapted to'engage .the ground plate uponfthe operationfoi1 the thermally-operable device near one edge of the ground' late arranged perpendicular to same, one o the electrodes of-thelightning arrester-engaging the'ground plate, andy a contactmember extending` from the thermallyfoperable devi'ee through the lightning arrester te contact the ground plate upon abnormal current conditions, to ground a cir- 6.. In apparatus-of the character,` described,

a ground plate,I a lightning arrester, an elecarrest-er to contact the groundplate when the said device is operated, substantiallyv as'de-l scribe 7. Iny apparatus of the character described, -a ground plate, a lightning arrester, an elec; tri-thermally-operablev device, said light ning arrester .being held aga-inst said'ground plate, and a contact member extending from the saidl' device .and arranged substantially perpendicular `to the ground plate, said contact member being arranged to extend through thelightningarrester and Contact ,the ground plate upon the operation oi the said device,=to ground a circuit.

8. 1 An electrothermal protector of the character described comprising a ground plate, a thermallv-operable device'arranged near one edge ofthe ground plate, the saidv device comprising a heating element. and suitable ter-- minals thereio'r, ametallic cupshaped portion inclosing the active portion of the heating element and secured b v solder thereto tol normalljsv hold the. heating element. from operating, and a contact member extending from' one of the said terminals through the 'cup-shapedportion and adapted to contact the ground plateA upon the operation of the device, substantially as described.

' 9 An electrothernial device comprising a heating element-'and a suitable terminal therefor,- a metallic casing inclosing the heating element and terminal. making.r contact with the heating elementand being insulated from the terminal, whereby the said casing, heating element and terminal are connected scribed, a n

pair of carbon disks with a sultable dielectric,

in series, a cup-shaped portion in lvvhichthe wholeis placed, heat-susceptible materialrbe-I tween thecu ishaped portion and 'the casing, normally holding: 'the la-t ter against move'- inent in the cup-shapedportion, atneck. portion extending from @recup-shaped )0rtion, and a pm -extendmg .tromthe sa1 Vcasing .through the neckportionpto operate-.to con-- trol a circuit .uponthe operation `ot'.tl 1e dei vice, .the said device being operable when the heat-susceptible material is softened b v eX,- cessive heating. y'

10. An electrothermal protector compris ing a heating element havingrv a spindle extending fizom either end thereof, a metallic sleeve stnrounding the active portion of fthe heat ing element and normally secured thereto by heat-susce )tible material, and means for Amoving the eating element longitudinally in the said sleeve when the heatesusceptible material is softened, whereby one of the said .spindles is caused towcontrol a circuit. t

11. In a paratus of the character described, a lightning arrester comprising va pair of carbon disks with a suitable dielectric interposed therebetween, an electrothermal devicev associated with Athe said arrester, a hole through the lightning arrester, and a. contact member extending lfrom the electrothermal device through the lightning arrester, said contact member .being utilized to control'a. circuit upon the'opration of the said device.

12. In a paratus of the character delightning arrester comprising a interposed therebetween, a hole through the center of the said disks, a' cup-shaped 'portion having -a flange bearing againstone of the said disks and a neck extending into the latter said disk, a heat-cartridge.contained in the said cup and normalhv held against operation'by-heat-susceptible material, a pin'extending from the said cartridge through the said flange and neck and into the said hole in the lightning arrester, and means for operating the heatcartridge within the said cup upon excessive heating to operate the'said pin through the lightning arrester to control a circuit. y

13. In apparatus of the character described, a groundplalte, a lightning arrester" and in'which the. latter is operable upon excessive heating@ terminal extending trom tlielieating element, und menus on the said terminall adapted to be pulled iipon to operate the l the heating element out of either end of theI sleeve. means for 'operating the said heating element loiigitudinnll)v in one direction in the sind sleeve, upon excessive heating, to 0:11150 one'of the siiidterniiiml portions to control n circuit, and means -oii one said terminal portion adapted to he pulled upon to operate thesaiid heating element longitudinally in the opposite direction in the said sleeve,`Wlien' properly heated, to reset the parts of the del vice tonorinal position.v for another operation.

16. A lightning arrester comprising@ line electrode and aground electrode, a. ground plate engaging the ground electrode, tlie" snid electrodes having a' hole therethrough, :i

through thaid hole to coiitaet the ground plate when the Said deviee'is operated.

As inventor of the foregoing, lI hereunto subscribe my naine in the presence ol two suliseiihing witnesses, this 20th day ot' Maile'. 1907.

FRANK B. oook.

Witnesses:

l"ni3DERIeK IL Piizxizii, JNO. F. ToMriuNs,

'thermally operaille devicex and ContactI i'neinlier extendingy from the said devise 

